FAQs from Rohde & Schwarz

FSW: Uncal for less then 10M, Use d.c. coupled

Question:

I have just purchased a FSW and there is an annoying message at the bottom of the screen which states, 'Uncal for less then 10M, Use d.c. coupled.'

How can I remove this message?

Answer:

The FSW has two input modes:

DC-coupled
AC-coupled

For low frequencies we need the DC-coupled mode, but with this mode any DC voltage can destroy the input.

So normally per default is the AC-coupled mode active, but this mode is not specified below 10 MHz.

I think your start frequency is below 10 MHz.

Then this message is coming.

If you now change the input mode to DC-coupled this message will disappear.